Screwdriver



J. E. MILLS.

SCREWDRIVER.

c APPLICATION man SEPT. 19. 1919.

Patented Oct. 18

auw/oo llar.

FATENT OFFIC JAMES E. MILLS, OF ST. LOUIS, MISSOURI.

SCREWDRIVER.

Specification of Letters Patent.

- Patented Dot. 18, ll92ll.

Alipucatiou mea septemter 19, 191e. serial ne. 324,872.

To all Le Imm t may concern.'

Be it known that l, JAMES E. MILLS, a citizen of the United States, andresiding at St. Louis, Missouri, have invented the new and usefulllmprovement in Screwdrivers, of which the following is a specication. y

This invention relates to screw drivers,

and more particularly to screw drivers ofthe type adapted to gripandretain a screw to faciliate its insertion and manipulation. ln screwdrivers of this type, as now constructed,'the gripping means operates toengage the screw head at the ends of the slot. Such a construction is,however, unsatisfactory because it not only fails to have the requiredrange. adapting. it to screw heads of different diameters, but moreoverit cannot be used for the insertion of screws which mustbe countersunk.

One of the objects of this invention, therefore, is to provide a screwdriver having an expansible element or tip which is adapted to enterslot of a screw so as to gripv in the slot and thereby retain the screwfor manipulation.l

Further objects will appear from the detail description taken inconnection with the accompanying drawing, in which:

Figure l is a side elevation of a screw driver embodying this invention;

Fig. 2 is a vlew similar to Fig. l, but

showing the expansible element in section;

Fig. 3 is a section on the line 3--3, Fig. 2;

Fig. 4 is a section on the line Ji- 4, Fig. 3; and

Fig. 5 is a detail of the expansible element.

Referring to the accompanying drawing, l designates a screw driverhandle which has a shank 2 provided at its end with the usual tip 3. Thehandle, shank and tip may be of any suitable construction, well known inthe prior art. l

Mounted on the shank 2 so as to be slidable therealong, is an expansibleelement 4. This element may be constructed of sheet metal formed toshape and it comprises a pair of jaws 5 which contract toward their freeends and are shaped to provide theelement 6 of a tip. The body of theadjustable element is provided with slots 7 and these slots receive lugsor ribs 8 struck -up from the shank. A knurled sleeve 9 -covers the endof the element and may be' secured thereto in any suitable .manner as byforced thereon. The expansible element is made of a. springy. material,such as sheet steel so as to have considerable resiliency and the tips 6may be hardened. These tips will thus be retained normally inengagement, due to the inherent resiliency of the metal. The expansibleelement can readily be assembled on the shank, and when in positionthereon and retained by the lugs 8 sliding in the slots 7 .and the wholesecured by the sleeve 9, the expansible element has a limited slidingmovement on the shank.

The operation and use of this device is as follows: The shank-2, withits tip 3, is Y l drawn into the expansible element so as to cause itstips 6 to'come together.V This tip can then be inserted in the slot of ascrew l0 and by then moving the shank toward the screw, the tip 3 wedgesbetween the jaws 5 so as to spread them apart and cause the expansibleelement to firmly grip in the slot ofl the screw head. The screw can nowbe inserted Vin its proper hole and driven. Where the fastening is alight one, the screw can be, driven home by the expansible tip; if,however, the fastening is a heavy one, then after the screw has beenstarted, the expansible tip is drawn back of the tip 3 as shown in Fig.2 and the screw is driven home by the tip 3. ,y

lt will, therefore, be seen that this invention accomplishes itsobjects. The device is exceedingly simple in construction and is suchthat it may be manipulated by the use of one hand; if the shank iswithdrawn into the expansible element thereby causing the tips 6 to cometogether, the latter can be readily inserted into the screw and. then bysimply pushing on the handle, the screw can be gripped; then after thescrew has been started, the expansible element may be drawn back by theengagement of the thumb with the knurled sleeve 9 to permit the screw tobe driven home by the main tip 3 on the shank of the screw driver.

In view'ofv the fact that the screw is gripped inside of its hole, theexpansible tip is adjustable to screw heads of different 4diameters andmoreover is adapted for structures Where the screw must be countersunk.

It is obvious that various changes ma be made in the details ofconstruction wit out departing from the spirit of this invention; it is,thereforejto .be understood that this inventionis not to be limited tothis-specie expansible thereby, adapted to grip and hold detail shownand described. l the screw While being' set, said starting 10 Havingthus described the invention, whatY tip being adapted t0 be moved clearof said is claimed is: driving tip While the screw is being driven. Ascrew driver, comprising e shank prolin testimony whereof l affix mysignature vided with e main screw driving tip, and a. this 11th day ofSeptember, 1919. double expansible storting tip on seid shank 5 andmovable beyond said driving tip, and JAMES E. MLLS.

